Porcelain jacket crown (PJC)

a brief about PJC and its steps for preparation

1. Porcelain Jacket Crown Dr. Bhupendra Rizal

2. All ceramic crowns are the most estheticlly pleasing restorations matching natural tooth structure in terms of color, texture, & translucency. THE FIRST ALL-CERAMIC CROWN WAS DEVELOPED BY “ LAND ” IN 1886. IT WAS CALLED AS PORCELAIN JACKET CROWN (PJC) Dr. Bhupendra Rizal

3. THE ORIGINAL PJC WAS MADE UP OF “ FELDSPATHIC PORCELAIN ” PREDOMINANTLY MADE OF SILICON DIOXIDE , WITH DIFFERENT FORMS,WHEN FUSES IT FORMS A GLASSY MATERIAL THAT GIVES THE PORCELAIN ITS TRANSLUCENCY Dr. Bhupendra Rizal

4. RECENT ADVANCES IN CERAMICS,ESPECIALLY ALL CERAMICS ALUMINIUM OXIDE ZIRCONIUM CASTABLE GLASS CERAMICS - DICOR CAD/CAM TECHNOLOGY IN DENTISTRY Dr. Bhupendra Rizal

5. Advantages Esthetics- superior translucency similar to the unrestored natural tooth. Good Tissue response Conservative facial tooth reduction as there is no metal sub structure. Colour of the luting cement influences & modifies the appearance of the restoration. Dr. Bhupendra Rizal

6. Disadvantages Reduced strength because of the absence of the metal substructure. Less conservative lingual & proximal tooth preparation. Significant tooth reduction required on the proximal & lingual surfaces as shoulder type finish line required. Difficulty in obtaining well fitting margin. Inadequate tooth preparation then restoration prone for fracture. Dr. Bhupendra Rizal

7. 90 degree cavo surface angle required to prevent the fracture as there will be favorable distribution of forces. Severely damaged tooth can not be restored as the preparation should provide support along the incisal edge. Not for FPD , although the In – Ceram Zirconia, IPS Empress -2 suitable for anterior sbut require 4x 4 mm connector with increased potential for periodontal failure. Wear of the opposing tooth Dr. Bhupendra Rizal

8. Indications The PJC are used: For anterior teeth (especially incisors). For discolored anterior teeth. An existing post and core substructure. 4 Endodontically treated anterior teeth. Dr. Bhupendra Rizal

9. Contra-indications The PJC are contraindicated: In posterior teeth (when maximum resistance and retention is needed). In case of tooth with short clinical crown (no enough tooth structure to support the porcelain). In case of edge to edge or overbite occlusion. As a retainer for FPD. Dr. Bhupendra Rizal

10. Tooth preparation Dr. Bhupendra Rizal

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